I started taking ballroom dance lessons way back in "1987". My wife and I started with group lessons through a community college, and then went on to private lessons thru an independent ballroom dance studio. All of our group lessons from the college were from the same instructor. When we started at the studio, we had our own private instructor, but also took group lessons (through the studio) from a variety of different instructors. The studio also brought in outside high level instructors (past or current champions) for special classes. As time went on, my wife had her own instructor (male) and I had my own instructor (female). We took separate privates and once a month took a private lesson together.
Complications started to develop because of the variety of instructors we were exposed to. I started to realize that occasionally I was getting conflicting information from these instructors. For example, I might get two different ways to dance the same pattern. In my simple mind, there was only one "right way". That means that the other way was "wrong". I later realized that both ways were "right".
Instructors teach different ways for many different reasons. Group lessons are typically taught at a much simpler level than private lessons. This is because of the number of students involved and also because of the variety of experience and background of the students.
Ballroom instructors aren't required by law to be trained or licensed; therefore, any one can declare that they are a "Ballroom Instructor". An untrained instructor usually teaches what they see; they don't necessarily know how it actually works. Consequently what they "see" is what you "get". However, don't assume that just because someone is a good dancer that they are good instructors. One of the worst lessons I have ever had was given by previous U.S. Ballroom Champions. Instructing is a different skill from dancing.
Trained instructors have to be constantly updating their skills all of the time because just like any other sport, ballroom dancing is constantly evolving. Instructors teach what they know and sometimes this information can be 15 years old if they are not evolving with the sport.
Sometimes instructors are hesitant to change what they are teaching because they think their students will think that they were teaching them wrong all along.
I personally try to teach everything to the extreme (even though it may be harder) because that generates the most feeling and dancing is all about feeling.
I always tell my students that the "right way" is in the opinion of your current instructor. Learn what your instructor is teaching exactly as it is taught and be able to dance it comfortably even if you disagree with him/her. Once you know how it works and feels, then you can decide for yourself if you are going to include all or part of it in your dancing. If you don't do this, you may be missing some very important little thing that you didn't' know before.
My instructor once told me: "You need to decide how you want you're dancing to feel". At the time I had no idea what she was telling me. I used to think that there was only one way to do something and it had only one way it should feel.
I like my dancing to be very connected and powerful while others like a very light connection (almost like dancing by yourself) and there is everything in between. I like to feel my other half as part of me while I am dancing. Try them all, and then decide what feels the best for you. In general, there is no wrong way, just a better way and YOU have to determine what the "right way" is!!!